Vauban under Siege is the first systematic comparison of the theory of Vaubanian siegecraft with its reality. It places Vauban’s siege accomplishments back into their broader context, highlighting his continuation of the quest for ever-greater efficiency pursued by a century of military engineers. Based on a comprehensive inventory of sieges in the War of the Spanish Succession, it describes how both French and Allied military officers rejected this efficiency paradigm and embraced instead vigorous brute force tactics.